The link-up was for technical services and did not involve equity cooperation, China Petroleum & Chemical Corp, or Sinopec, said on its official microblog. It did not say how much money was involved.

Cooperation between Alibaba, a poster child for private enterprise in China, and one of the country's biggest state-owned companies dovetails with government policy.

Sinopec and other state behemoths have been under pressure to make better use of information technology and take advantage of cloud computing and big data to better track things like supply, demand and emissions.

Alibaba, whose $25 billion initial public offering in New York in September was the biggest on record, has been leveraging its good standing with the government to forge cloud computing agreements with various government or state-run bodies.

"By helping Sinopec with digitization and big data technologies, we hope we can play a part to help bring about greener solutions and new business opportunities," Allen Zhang, director at Alibaba's cloud computing business Aliyun, said in an emailed statement.

The cooperation between Aliyun and Sinopec would help upgrade some of the oil company's traditional petrochemical services, Sinopec said.